It's impossible to steal a trad tune, otherwise somebody should start Threads: Stolen melodies/Michael Scanlan ('Bold Fenian Men', 1864)/Carter Family/Woody Guthrie, Tom Paxton,Phil Ochs, and so on ad infinitum.

As Dave Van Ronk wrote, 'Paul Clayton, he was one of my closest friends... he found a song called 'Who'll Buy Your Chickens When I'm Gone' wwhich he changed to 'Who'll Buy You Ribbons'...not a masterpiece but it got to be a great point of contention later on when Dylan copped the melody and a couple of lines for 'Don't Think Twice'. (from 'The Mayor of MacDougal Street: a memoir' (2005). I think the key question is did Clayton write the melody? I doubt it.

So Dylan's name is Zimmerman? Correction: it was Zimmerman. He changed it to Bob Dylan by deed poll in 1962 (see Suze Rotolo's book).

btw, Good SS (!), how do you know that Dylan took the name from Dylan Thomas? He has always refused to say. I think he probably did tho nobody has proved it yet. The 'great' Welsh poet Dylan Thomas wrote a lot of old mumbo-jumbo anyway! If he were alive today, he'd probably change his name to Dylan Zimmerman!